Faster, practical keyboard

ABSTRACT

A keyboard for computers and data entry devices is disclosed, which increases typing speed, but at the same time eases the transition from the Standard Qwerty keyboard for experienced typists. Two letter sequences called digraphs are typed rapidly when struck by opposite hands. The proposed keyboard places frequently used digraphs on opposite hands and avoids the use of small fingers to increase typing speed. The home row is not emphasized and only three high frequency letters are moved relative to Qwerty positions, making the keyboard easy to learn. The constraints of maximal speed and minimal modification are satisfied concurrently. A second key is dedicated to the letter “E”, the most frequently used letter in the English language, to further enhance typing speed and ease of transition from Qwerty. The result is a faster and highly practical electronic keyboard.

TECHNICAL FIELD

A keyboard for computers or electronic data entry devices, adapted fromthe Standard Qwerty keyboard for ease of transition by experiencedtypists, with speed maximized by separation of frequent lettercombinations, or digraphs, and through avoidance of awkward letterlocations.

BACKGROUND ART

List of References Cited in This Section (United States Patents)2,040,248 May 12, 1936 Dvorak 3,847,263 Nov. 12, 1974 X 5,166,669 Nov.27, 1992 Romberg 5,836,705 Nov. 17, 1998 Choate 5,879,089 Mar. 9, 1999Armel 6,053,647 Apr. 25, 2000 Parkinson

The preferred embodiments of the keyboard patents listed here are shownin FIGS. 2 through 7 of the Drawings, for ease of reference. Anadditional list of world-wide keyboard patents is also included below.The members of that list have some common attributes, which allow themto be addressed as a group.

Standard Qwerty Keyboard

The current Standard keyboard is also known as the Qwerty keyboard,based on the first six letters on the left hand side of the upper row ofalphabetic characters. It was designed for mechanical typewriters around1872 by C. Latham Sholes. Letters were arranged to prevent the jammingof mechanical keys, a design which also slows down typing. The Qwertykeyboard is poorly optimized for speed on an electronic keyboard, wheremechanical key interference is no longer an issue. Regardless, theQwerty keyboard is familiar to most keyboard users and Is wellentrenched in industry. Many improved keyboards have been proposed asalternates to the Standard, but these alternatives have not been broadlycommercially accepted over the past one hundred and thirty years.

Dvorak Keyboard

In U.S. Pat. No. 2,040,248, of May 12, 1936, August Dvorak and WilliamDealey revealed an improved keyboard, with respect to the speed oftyping and the reduction of finger reach and strain. They recorded thefrequency of two letter sequences in the English language, calleddigraphs. Using this data, awkward key patterns were avoided, such asstriking different keys with the same finger. The most frequently usedletters were placed on the middle or “home” row, to minimize fingerreach and potential strain. Due to the speed improvements and reducedstrain which it offers typists, the Dvorak keyboard is widelyacknowledged in industry as a keyboard design that is superior to theQwerty keyboard.

One drawback of the Dvorak keyboard is the random placement ofalphabetic characters, virtually all of which are in different locationsfrom the Standard Qwerty keyboard. This makes transition from the Qwertykeyboard quite difficult. Another problem exists, in that two frequentletters, A and S, appear at small finger locations on the home row.Dvorak mentions that use of small fingers in typing is awkward, butplaces A and S at such locations regardless, so that all high frequencyletters except R appear on the home row.

“X” Keyboard

In a Nov. 12, 1974 patent, U.S. Pat. No. 3,847,263, an alternate to theDvorak keyboard was introduced by “X”, with many of the same attributes.For example, “X” positions most frequently used keys on the middle orhome row of the keyboard. Letter frequencies in foreign languages otherthan English are also considered. The “X” keyboard has both dextral andsinistral versions, aimed at use by persons with dominant right and lefthands, respectively. All vowels appear on the left hand side of the “X”keyboard, in its dextral version. Most vowels and consonants areinterleaved in language, so this places many sequential key combinationson opposite hands. High frequency keys appear at both small fingerlocations in the “X” Keyboard. With many high frequency keys on themiddle row, the “X” keyboard offers greater speed potential to a typist,relative to the Qwerty keyboard.

The two main drawbacks of the “X” keyboard are similar to those of theDvorak keyboard. The “X” keyboard has a random arrangement of alphabeticletters, almost all of which differ from the Standard Qwerty locations.A new random arrangement of letters is seen as a significant barrier tothe wide-spread use of any keyboard. As well, the “X” keyboard placestwo frequently used letters at small finger locations, namely O and S.This is seen as problematic, because small fingers are often less agilethan other fingers.

Romberg/ASER Keyboard

U.S. Pat. No. 5,166,669 was granted Nov. 27, 1992, to Harvey D. Romberg.It outlines a keyboard layout aimed at reducing the difficulty intransition from the Standard Qwerty keyboard. A maximum of fifteen keysare moved from their Qwerty locations. Several high frequency lettersmove from their Qwerty locations to the home row, as occurs in Dvorakand “X” keyboards. The left hand side of the home row begins with theletter sequence A, S, E, R, leading to the name ASER Keyboard. Thearrangement reduces finger reach from the home row to upper and lowerrows. Reach reduction is aimed at both improving speed and reducingrepetitive strain injuries.

Limitations are seen in the ASER keyboard. Six high frequency lettersare moved to the home row, namely the letters: E, R, N, T, I and O.Because these letters are so common, it is remains difficult for a touchtypist or a hunt style typist to adjust to the change. The goal ofeasing transition from the Qwerty layout is only partially achieved.Next, the ASER keyboard patent description does not explore digraphs orkey sequences. Analysis shows that it is not well optimized in terms ofplacing digraphs on opposite hands. As well, the small finger is usedfor two high frequency letters on the home row, namely A and O. The lasttwo factors indicate some limitation with respect to typing speed.

Choate/Red Hot Keyboard

Preceded by similar patents in 1994 and 1996, U.S. Pat. No. 5,836,705was granted to John I. M. Choate on Nov. 17, 1998. Choate introduced akeyboard identified by the high frequency letters “As in Red Hot” on themiddle or home row. Similar to the Romberg approach, there was a directeffort in the keyboard design to ease transition from the StandardQwerty layout. No more than 16 letters move from their locations on theQwerty layout, in “Red Hot” realizations of a keyboard. Six highfrequency letters (E, I, O, T, N and R) are moved from Qwerty locationsto new home row locations. The emphasis on home row letter location byChoate is aimed at reducing finger reach. Choate presents statisticsshowing that the Red Hot keyboard design significantly reduces “fingerdistance” traveled. This attribute is aimed at a reduction in repetitivestress injuries and carpal tunnel syndrome.

Choate also examines briefly the digraph statistics developed by Dvorakand Dealey. Choate notes that many of the frequent digraph pairs are nowlocated on the home row, again reflecting a design aimed at reducing“finger distance” traveled. Placement of digraphs on opposite hands isnot discussed by Choate and the layout is not optimized in that regard.

The main limitations seen in the Red Hot keyboard layout are similar tothose of the ASER layout, discussed above. That is, six high frequencykeys move from their Qwerty locations, so that transition from thestandard may not be as easy as intended. As well, two high frequencyletters (A and R) appear at small finger locations, which are awkwardlocations for many typists. Last, neither ASER nor Red Hot keyboards areoptimized with respect to placement of high frequency digraphs onopposite hands. For the latter two reasons, there are typing speedlimitations on both the ASER and Red Hot keyboards, as well as someongoing difficulty in transition from Qwerty.

Armel/Central Keyboard

Another novel keyboard design was introduced by Gerald J. Armel, in U.S.Pat. No. 5,879,089, dated Mar. 9, 1999. Armel places an emphasis on thecentral region of the keyboard, which may be reached by the strongestand most dexterous fingers, the middle finger and forefinger, alsocalled the “inner fingers”. As used here, the term “finger dexterity”includes both the physical and mental aspects of finger control andmovement.

A preferred embodiment of the Armel/Central Keyboard shows the mostfrequently used letters of the English language, in the center of theupper, middle and lower rows of the keyboard as follows: upper row S, T,R middle row N, E, A lower row I, O, UThis Central keyboard arrangement designed by Armel was aimed at userswho may have difficulty using fingers other than inner fingers, for avariety of reasons.

One issue that arises with the Armel keyboard, is the placement ofletters in “random” locations, nearly all of which are different fromStandard Qwerty locations. History shows that this is a major inhibitorto keyboard adoption in practice. In addition, the Central keyboarddiscussed here is not well optimized with respect to placement ofdigraphs of opposite hands. A central positioning of high frequencyletters causes many key sequences to be performed by the same finger orby adjacent fingers. These factors suggest fundamental speed limitationsin the Armel or Central keyboard layout.

Alphabetic Keyboards

There are a quite a number of keyboard patents which include key layoutsin alphabetical order as one of their characteristics. So called“Alphabetic” keyboards have been defined as early as May 28, 1985, inU.S. Pat. No. 4,519,721, by Kathleen A. Gardener. A more recentAlphabetic keyboard is found in U.S. Pat. No. 6,053,647, dated Apr. 25,2000, by John V. Parkinson. The Parkinson patent is chosen for referencebecause it discusses the optimization of two key sequences, or digraphs,and claims to be better than the Dvorak layout, in this respect. TheParkinson analysis is confined to digraphs on the same row. When theanalysis is expanded to frequent key sequences on two rows, as outlinedherein, both the current invention and the Dvorak keyboard are seen tobe better optimized for digraphs on opposite hands than the ParkinsonAlphabetic keyboard implementation of the year 2000.

Alphabetical order is aimed at ease of learning for new users or thosewho only use a keyboard infrequently. The logical arrangement of keys inalphabetical order makes letters easier to find and to remember, incomparison to a random layout. This is of benefit to entirely new usersor possibly persons who must only use keyboards infrequently.

Alphabetic arrangements of keys represents a total departure from theStandard Qwerty arrangement of keys. Because there are many existingkeyboard users, who are familiar with the Qwerty layout, there will bean on-going barrier to adoption of an Alphabetic key layout.

The interleaving of vowels and consonants in the order of the alphabetmakes it difficult to optimize such layouts for speed. A predeterminedletter ordering, whether along rows or columns, Inhibits placement ofdigraphs on opposite hands, which is an important factor for speed.Parkinson has tried to optimize this factor and may be considered“best-in-class” among Alphabetic keyboards. Still, both the currentinvention and the Dvorak keyboard place more digraphs on opposite hands.As such, the current invention is expected to be faster for typing andeasier for Qwerty transition than Alphabetic keyboards in general.

Other Keyboard Arrangements (US, International and PCT/WIPO Patents) WO01/73744 A1 Oct. 4, 2001 Woods, Debra L. WO 9906216 Feb. 11, 1999Pittard, Arthur George U.S. Pat. No. 4,927,279 May 22, 1990 Morgan, RuthB. FR 2611589 Sep. 9, 1988 Marsan, Claude U.S. Pat. No. 4,332,493 Jun.1, 1982 Einbinder, Harvey EP 0066991 Dec. 15, 1982 Rushforth, ShelaghJane GB 2041295 Sep. 10, 1980 Marsan, C. U.S. Pat. No. 3,929,216 Dec.30, 1975 Einbinder, Harvey U.S. Pat. No. 3,698,533 Oct. 17, 1972 Illiget al. U.S. Pat. No. 3,698,532 Oct. 17, 1972 Dodds, Irvine U.S. Pat. No.1,506,426 Aug. 26, 1924 Hoke, R. E. U.S. Pat. No. 1,512,001 Oct. 14,1924 Cerny, J.

All of the above keyboard layouts share one important characteristic:the letter arrangements are entirely different from the Standard Qwertykeyboard and the majority of letters have moved from their Qwertylocations. Clearly, the patents listed here do not have ease oftransition from the Standard Qwerty keyboard as one of their primaryobjectives or attributes. As such, they fall into a very differentcategory from the current invention, which includes that constraint asone its primary goals.

The second and concurrent goal of the current invention is to increasethe speed of typing. As outlined above, the Dvorak and “X” keyboardshave been designed with that goal in mind. Both Dvorak and “X” keyboardshave layouts which include the vowels A, E, I, O, and U on the left handside of the middle row of the keyboard. This is a characteristic sharedby a number of the patents listed here, namely: Pittard 1999, Marsan1988 and 1980, Einbinder 1975, Dodds 1972, and Cemy 1924. As a group,they may be called “vowel oriented” keyboards. By separating vowels fromhigh frequency consonants, frequent key sequences appear on oppositehands. Such a separation is one of the main elements contributing tohigher speeds of typing on a keyboard.

It is not viewed as necessary to analyze in detail the behavior of allvowel oriented keyboards, to demonstrate that the current invention isnovel and different from the group. Rather, it is felt to be sufficientto examine the keyboard which is generally acknowledged as“best-in-class” with respect to typing speed, namely the Dvorak keyboardfrom 1936. As evidence of that stature, the Dvorak keyboard is includedas a “Language-Property” option in most versions of the MicrosoftWindows Operating System (OS), and can be readily installed on computerswith a Window OS. A second keyboard, the “X” arrangement of 1972 isanalyzed in detail in this document. Examination of further individualvowel oriented keyboards is viewed as likely to be redundant; theirbehavior or properties are expected to fall within the range ofbehaviors exhibited by the Dvorak and “X” keyboards.

Multiple Letter Keyboard—Marsan, 1988

The 1988 patent by Marsan may be worth a brief mention, since itcontains an example of a keyboard with multiple keys assigned to thefrequent letters E and A in the French language. The multiple letters inthe Marsan case are aimed at providing easy access to the use of accentsgrave (è) and aigu (é) on the letter E and accent grave on the letter A.This is not an uncommon approach to speeding typing on European languagekeyboards, which may apply a variety of accents to letters, oftenvowels. In the Marsan example, the variants of the letters E and Aappear close to one another on the same side of the keyboard. In thecurrent invention, two E keys are placed on opposite sides of thekeyboard, with the objective of increasing the frequency of keysequences that may be struck by fingers of opposite hands. The usage ofmultiple keys in the current invention is different from that of theMarsan, 1988, keyboard or other keyboards with separate keysrepresenting accents on vowels or other letters.

Concluding Remarks on the Background of the Invention

As noted above, vowel oriented keyboards are considered as a group, andthe best performing keyboards in that category, the Dvorak and “X”keyboards, are examined in detail in this document, as background to thecurrent invention.

Attributes of the Romberg and Choate keyboards are examined in detailherein, because those two arrangements are specifically aimed at easingtransition from the Qwerty keyboard; no other keyboards have beenidentified with that stated objective. The Armel or Central keyboard hasbeen examined, because of its emphasis on inner fingers, which issomewhat similar to the avoidance of small fingers. It is problematic interms of transition from Qwerty, as well as speed potential.

An Alphabetic keyboard example was examined, since there are severalknown variants of keyboards with letter arrangements in alphabeticalorder, either along rows or up and down columns. All are similar,however, in that they constrain consonants in a manner that does notlend itself to optimization of key sequences on opposite hands. Thealphabetical order chosen dictates consonant positions in each case.This imposes inherent speed limitations.

A patent by Marsan of 1988, with multiple occurrences of the frequentletters A and E, is seen to be quite different in design and intent thanthe current invention.

It is hoped, therefore, that the examination of existing patents andknown keyboard designs, as covered in this document, may be acomprehensive review of the subject for the purpose of differentiatingthe current invention.

DISCLOSURE OF THE INVENTION SUMMARY

The instant invention is called the “XPeRT Keyboard”, where the term“XPeRT Keyboard” is an unregistered product trademark. The currentStandard keyboard is identified as the Qwerty keyboard, based on theletters Q, W, E, R, T, Y, on the left hand side of the upper row of thealphabetic character area. This sequence is replaced by the lettergroupings X, P, E, R, T or X, P, R, T in the instant invention, todistinguish it from Qwerty. At the same time, as many letters aspossible are kept in their current Qwerty locations, to ease thetransition to the new keyboard for experienced typists. In particular,as few high frequency letters are moved as possible, while achievingsubstantial speed improvements. As few as three high frequency lettersmove from their current locations, namely: A, N and E.

In the most highly optimized version of the “XPeRT Keyboard”, only thehigh frequency letters A and N move from their Standard Qwertylocations. The letter A moves to the right hand side of the keyboard andthe consonant N moves to the left hand side of the keyboard. A secondkey for the letter E is created and placed on the right hand side of thekeyboard. At the same time, a key with the letter E remains at itscurrent Qwerty location, so that the high frequency letters E, I, O, R,S and T remain accessible in their current Qwerty locations. The effortin relearning the keyboard layout is thereby minimized. E occurs almosttwice as frequently in the English language as other high frequencyletters, so this treatment of the letter E, splitting its use acrossboth hands, is quite powerful.

In a slightly less optimized version of the “XPeRT Keyboard”, there isonly one key with the letter E, and it is moved to the right hand sideof the keyboard. The letters R and T may be shifted to the right one keyeach, to fill the gap left by E, so that the acronym “XPRT” is created.The “XPeRT Keyboard” version which uses only one E still has many of theadvantages of the version with two keys for the letter E, as discussedin detail later.

While moving as few frequent letters as possible, the new “XPeRTKeyboard” has been optimized for speed. This is achieved mainly byplacing frequent key pairs or digraphs in locations that are to bestruck by fingers on opposite hands. Using digraph frequency statistics,the probable number of key sequences to be stuck by fingers of oppositehands for a given keyboard layout are tabulated. This measure ofopposite hand use is identified as a primary factor contributing to thespeed of a keyboard. The “XPeRT Keyboard” is optimized for this digraphfactor, and is thereby optimized for speed. Tabulations and furtheranalysis on this subject are presented in the Detailed Description ofthe Invention.

Unlike Dvorak, “X”, ASER and Red Hot keyboards, the majority of highfrequency keys are not placed on the home row of the “XPeRT Keyboard”.Placing frequent letters on the home row reduces finger reach andassists in reducing finger strain, but It is not the only way toincrease typing speed. For many typists who do not use a keyboard eighthours a day, lowering finger strain is less important than typing speed.

To further improve typing, the “XPeRT Keyboard” places none of the highfrequency letters A, E, I, O, N, R, S, and T in locations accessed bysmall fingers. Partly because it shares a tendon with the ring finger,the small finger is the least dexterous of all fingers. Its use remainsawkward for many typists. In contrast to the “XPeRT Keyboard”, theDvorak, “X”, ASER and Red Hot keyboards all have two high frequencyletters in awkward small finger locations, due to an emphasis on thehome row. The “XPeRT Keyboard” offers an improvement over home roworiented keyboards, through avoidance of positioning high frequencyletters at locations to be accessed by awkward small fingers.

The “XPeRT Keyboard” is novel and unique because it is able tosimultaneously resolve more conflicting constraints than existingkeyboards. It is designed to be as fast as Dvorak or “X” keyboards,without having similar problems in transition from Qwerty. By movingonly three high frequency keys, it is best optimized for ease oftransition from Qwerty, while offering higher typing speed potentialthan alternatives. Creation of a second key dedicated to the letter Efurther enhances these attributes of the “XPeRT Keyboard”.

DETAILED DESCRIPTION OF THE INVENTION

The design objectives for the “XPeRT Keyboard” are listed here and areexpanded upon below, by subject area:

Ease of transition from the Standard Qwerty keyboard; minimizing of thenumber of characters which change key locations.

Making frequently used keys accessible by more dexterous inner fingersand placing frequently used keys on the home row or retaining them inupper row positions.

Maximizing the potential for speed, by placing high frequency digraphson opposite sides of the keyboard and avoiding small finger use.

Creation of a second key for the letter E.

Evaluation of the “feel” of the keyboard, based on user feedback.

Replacing the familiar Qwerty pattern on the left side of the top row ofthe keyboard by a readily recognizable set, namely X, P, R, T or X, P,E, R, T.

Qwerty Transition

This design consideration is almost self explanatory, although it hasnot been universally embraced by all keyboard designs. The resistance tochange from the Standard Qwerty keyboard is best illustrated by the factthat the Qwerty layout remains dominant, after 130 years. It persistsdespite the fact that it is poorly optimized for typing on electronickeyboards, where the problem of mechanical key jamming due to rapid keystriking has been eliminated.

In practical typing applications, the only hope for transition fromQwerty is seen in a keyboard which retains most of the letter placementsin Qwerty. The “XPeRT Keyboard” moves only two to three high frequencykeys to another row. All other moves are limited to medium and lowfrequency keys. It is believed that these minimal impact letterrelocations will encourage users to experiment with the “XPeRT Keyboard”and will allow them to reach former levels of competency in typing in aminimum amount of time. Thereafter, the larger benefits to typing, asoffered by the “XPeRT Keyboard” layout, will accrue.

Qwerty Letter Locations, by Key Number

FIG. 1 shows the alphabetic character or letter layout of the Standardcomputer keyboard in use today in Canada and the U.S. Western Europeankeyboards are similar, with few letters moved. The letters on the lefthand side of the upper row are Q, W, E, R, T, Y, which are often used toidentify the Standard as the Qwerty keyboard. All letters of thealphabet have been numbered as elements from [1] to [26] in FIG. 1,where the sequential numbers identify the locations of the letters, andthe key positions, of the Standard Qwerty keyboard, as follows:

Key numbers 1 to 10 correspond to letters Q through P, from left toright

Key numbers 11 to 19 correspond to letters A through L, from left toright, and

Key numbers 20 through 26 correspond to letters Z through M, from leftto right

In this manner, key positions are identified by unique numbers, or keynumbers, relative to the alphabetic characters on the Qwerty layout. Keynumbers defined here will be used from time to time to identify theplacement of letters in this section and in the Preferred Embodiment ofthe Invention. Key numbers of the Qwerty letter layout are explicitly:

Q-[1], W-[2], E-[3], R-[4], T-[5], Y-[6], U-[7], I-[8], O-[9], P-[10],

A-[11], S-[12], D-[13], F-[14], G-[15], H-[16], J-[17], K-[18], L-[19],

Z-[20], X-[21], C[22], V-[23], B-[24], N-[25], M-[26].

The punctuation mark semi-colon in FIG. 1 is associated with key number[27].

Frequently Used Keys to be Accessible by Inner Fingers and on the Middleor Upper Rows of the Keyboard

The frequency of occurrence of letters in English language, in popularnovels and newspapers, has been derived by the author in percentageterms. Findings for Single Letter Frequencies are as shown in Table I,below.

The statistics in Table I are similar to letter frequencies quoted inother studies. More commonly accepted frequencies are: H-3.5% and N-7.8%and E-13.0, so that N is regarded as one of the set of eight highfrequency letters, while H is treated as a moderate frequency letter.Other letter frequencies vary slightly also, but are not viewed asmaterial to overall analysis. In the course of typing in the Englishlanguage, the letter E is struck almost twice as frequently as any otherletter, including the higher frequency letters. TABLE I Single LetterFrequency in English letter frequency a 7.5% b 1.1% c 3.0% d 3.4% e12.2% f 3.1% g 2.3% h 6.0% i 7.6% j 0.1% k 0.7% l 3.3% m 2.6% n 6.0% o7.9% p 2.0% q 0.1% r 6.7% s 6.7% t 9.8% u 2.8% v 1.0% w 2.0% x 0.3% y1.8% z 0.0%Groups of high frequency, medium frequency and low frequency letters areidentified next. In summary:

The eight most frequent letters in English are: A, E, I, O, N, R, S, andT, representing roughly 66% of all keystrokes; of these, E representsroughly 12% to 13% of all keystrokes in English

Eleven medium frequency letters in English are: D, F, G, H, L, M, P, U,W and Y, covering roughly 31% of keystrokes

The seven lowest frequency letters in English are: J, K, B, Q, V, X, andZ, representing just over 3% of all keystrokes

The objective is to place the most frequently used letters so that theyare accessible by inner fingers or on the middle or upper rows, whileminimizing change from Qwerty. With reference to letter locations on theStandard Qwerty keyboard, as shown in FIG. 1 of the Drawings, the “XPeRTKeyboard” layout incorporates the following movement of letters:

R, T, I, and O are retained on the upper row,

A, E and N are moved to inner finger locations on the home row; A and Emove to the left hand side and N moves to the right hand side of thekeyboard, and

S remains stationary on the home row

The letter A has moved away from an awkward small finger location, to adexterous forefinger location on the right hand side of the middle row.Low frequency letters J an K are located in prime positions on theQwerty keyboard and are good candidates for replacement by A. Havingmoved A, it was decided to move N from its lower row location, so thatit need not be struck by the same finger as the letter A. S was moved atone time also, but movement of more than two or three high frequencykeys proved problematic for users. The E key was moved for reasonsoutlined in the next topic.

Optimization of Speed via Digraph Frequency

The digraph frequencies listed in Table I of Dvorak's 1936 patent havebeen combined, as shown in Table II, titled Digraph Frequency Sums,below. The statistical values for letter pairs such as ER and RE havebeen added together; otherwise the data remains unchanged. The relativeposition of ER will be the same as the relative position of RE on anykeyboard, so this tabulation of the data lends itself more readily to anaccurate analysis. In Table II the key pair statistic is found at theintersection of rows and columns headed by various letters. The totalvalue of all key pair data on Table II is 3320. The relative value forthe key pair EH and HE is 117, which may be stated as EH(117). Thepercentage occurrence of the key pair in English is therefore117+3320×100%=3.5%. Other high frequency key pairs are ER(162) at 4.9%.and TH(149) at 4.5%.

In the 1936 patent document, Dvorak focused his analysis on avoidance ofawkward key sequences, such as striking two different keys with onefinger or jumping from the upper to the lower row, using the same hand.Oddly, he mentions that small finger locations are awkward for a typist,but places the high frequency keys A and S at those locations on themiddle row, regardless. The subject of digraphs on opposite hands doesarise in the Dvorak patent, but the manner in which his keyboardsupports this factor is not explicitly presented.

Opposite hand digraph placement will be analyzed briefly here, tosupport its usage as a major factor in typing speed optimization. First,take the simple example of the letter combinations, TH and SO, aslocated on the Qwerty keyboard. These letter pairs appear on differentrows and on opposite sides on the keyboard. A quick test reveals that itis easy to achieve a speed of roughly 100 words per minute (wpm), whentoggling the nonsense word “SOSO”, in lower case with no spaces.Alternately, toggling adjacent inner fingers is nearly as fast at times,but this action has a more limited scope. For example, on the standardQwerty layout, toggling the key pair JI is fast, whereas UK is not. Bothactions involve the inner fingers on the top and middle rows, but reachbecomes a problem for the UK sequence

Reach becomes a major issue for fingers of the same hand, whereas it ismuch less of an issue when fingers are on opposite hands. A test wasconducted on the Qwerty layout for two phases, namely: “the island is”and “as great as cats”. The first phrase has letters on all three rowsand good placement of key sequences across opposite hands: TH, HE, EI,IS, SL, LA, AN, and ND. In fact, each sequential key is struck by anopposite hand. Conversely, the second phrase is located mainly on theleft hand side of the keyboard, so that typing is almost exclusive tothe left hand and use of adjacent fingers. The awkward sequence AS(49)is included. The two contrasting phrases have been chosen to illustratethe benefits of placing sequential key strokes on opposite hand, versussame hand arrangements.

For right handed typists, using a hunt style of typing rather than touchtyping, there were dramatic differences in the speed with which the twophases could be typed. On the Qwerty keyboard, typing “as great as cats”repetitively took roughly 50% more time than typing “the island is”,with an equal number of total letters struck in each case. Conversely,on the “XPeRT Keyboard” with one E key, typing “as great as cats” wascomparable in speed to typing “the island is” (there was some minorvariation in test results). Because A and E are on adjacent innerfingers and on the same row, their action is fairly rapid; such designfactors have been considered in the “XPeRT Keyboard”.

Optimal usage of the data in Table II is a significant challenge. Dvorakmade this task somewhat easier by allowing all letters to move to newrandom locations, thereby increasing the degrees of freedom in thesolution to the problem. The objective of the “XPeRT Keyboard” is quitedifferent and significantly more difficult: To optimize letter placementusing digraph data while simultaneously minimizing transition from theQwerty layout. This has proven to be a major challenge. At the end ofseveral months of analysis and experimentation, an elegant and powerfulsolution was discovered. While it may not be the perfect solution, ithas many positive attributes.

The least disruption is caused to the Qwerty keyboard by moving A and Eto the right hand side of the keyboard, while N moves to the left handside. With these three elegant moves, the Qwerty keyboard is transformedfrom “digraph disabled” to “speed enabled”. Some low frequency keys mustbe moved to accommodate the change, but this has a lesser impact. Atthis point, many of the goals of the “XPeRT Keyboard” have beenachieved.

Creation of a Second Key for the Letter “E”

A further advantage is achieved by creating a second key dedicated tothe letter E, so that the letter E appears in its original Qwertylocation, as well as on the right hand side of the keyboard. First, thisovercomes much of the relearning obstacle introduced by moving the mostfrequent letter in English. Second, it splits the usage of the letter Eacross two hands. It allows E to be struck say 5% of the time by theleft hand and 8% of the time by the right hand. Although E is struckalmost twice as often as other keys, by this means the fingers used forE become no more tired than other fingers. Last, and equally asimportant as keeping E In a familiar location, the second E enables morehigh frequency digraphs to appear on opposite hands. Moving E to theright hand side enables ER(162), ET(65), ES(57) and several other highfrequency digraphs. Keeping E in its old location enables additionalimportant digraphs, such as EH(117), EM(50) and EL(42), among others.

The degree to which digraphs are located on opposite hands may bequantified. In doing so, an opposite hand “digraph factor” is defined.The “XPeRT Keyboard” of FIG. 10 has been analyzed in this manner anddetailed results appear in Table III. The data values in Table III havea total of 2643, or just under 80% of the total digraph frequency datavalues in Table II, namely 3320. Beyond this range, many more scattereddigraph frequencies occur, which have low impact on typing speed. InTable III, it is seen that the “XPeRT Keyboard” with two E keys ishighly optimized for digraph placement on opposite hands. Very fewdigraphs remain on the same hand. OU(98) and ND(72) are not tooproblematic, since they are on the same row. AH(66) is a slight problemand will be discussed later.

The other keyboards discussed here and shown in FIGS. 1 through 9 of theDrawings have also been examined in terms of the opposite hand digraphfactor defined in Table III. Totals were derived for each keyboard andthe results are listed in Table IV. Note that the “XPeRT Keyboard” withonly one E key, shown in FIG. 8, is similar in layout to FIG. 10. The“XPeRT Express Keyboard” example, shown in FIG. 9, builds on thekeyboard in FIG. 8 and has six more keys moved from their Qwertylocations.

The “XPeRT Keyboard” compares favorably against the Dvorak and “X”keyboards, in Table IV. All other novel keyboard arrangements listed donot show strength in the opposite hand digraph factor defined. Rather,other keyboards have opposite hand digraph factors which hover aroundthe value for random distribution, namely 50%. This is not the onlyfactor affecting typing speed, but it is an important one, as explainedabove. Therefore, the results in Table IV indicate a fundamentallimitation with respect to speed, for all keyboards listed, with theexception of the Dvorak, “X”, and “XPeRT Keyboard” versions.

As mentioned earlier, the Alphabetic keyboard patented by Parkinson in2000, claimed to be better optimized for digraphs on opposite hands thanthe Dvorak keyboard. The analysis was focused on digraphs which appearon the same row only, however. In the Dvorak keyboard the letter Rappears on the upper row, while most other high frequency letters are onthe home row. By limiting analysis of the Dvorak layout to digraphs onthe same row, high frequency digraphs involving R, such as: AR(46) andRO(65) and ER(162), the highest of all values, are not considered. Theseare not difficult combinations for a typist on the Dvorak keyboard, andthe single row analysis is felt to be too narrow.

When digraph analysis is expanded to include digraphs above 20 in valuefrom Table II and to include digraphs on opposite hands regardless ofthe row on which they appear, then the results shown in Table IV areobtained. It is noted that there are many digraphs with a frequencyvalue of greater than 20, so this group has a noticeable impact ontyping. Experiments and practical experience show that moving from anupper row to the home row, or between adjacent rows, only slightlyreduces the benefit to speed of having digraphs struck by oppositehands. The broader analysis is meaningful and of practical value. TABLEII Digraph Frequency Sums a b c d e f g h i j k l m n o p q r s t u v wx y z a b 12 c 28 d 30 e 25 34 38 38 f 7 11 g 8 16 h 66 20 117 9 i 9 315 19 13 18 11 35 j k 6 4 10 7 l 41 5 4 16 41 1 2 34 m 30 2 50 15 n 92 972 66 1 33 88 10 2 o 0 11 22 16 1 62 14 20 12 3 18 33 44 p 12 14 4 11 413 q 1 r 46 2 13 162 9 3 2 22 2 2 4 5 65 8 s 49 2 1 57 16 53 2 2 1 4 291 12 t 64 6 65 3 149 72 3 24 85 3 12 32 u 1 13 7 1 3 8 1 2 5 14 7 12 988 3 44 27 28 v 22 2 59 0 13 7 1 w 17 42 19 32 1 2 31 5 1 2 x 4 1 1 y 214 1 10 13 8 8 58 1 15 3 4 ztotal of all data values on the table: 3320

TABLE III Digraphs on Opposite Hands for the “XPeRT Keyboard” with Two“E” Keys Digraph Frequency Sums Keystrokes on Hands Pair ValuePercentage Oppo Same Oppo Same er 162 6% 1 162 0 th 149 6% 1 149 0 he117 4% 1 117 0 ou 98 4% 1 0 98 an 92 3% 1 92 0 in 88 3% 1 88 0 to 85 3%1 85 0 on 76 3% 1 76 0 nd 72 3% 1 0 72 it 72 3% 1 72 0 en 66 2% 1 66 0ah 66 2% 1 0 66 or 65 2% 1 65 0 te 65 2% 1 65 0 at 64 2% 1 64 0 re 59 2%1 59 0 yo 58 2% 1 58 0 of 58 2% 1 58 0 es 57 2% 1 57 0 is 53 2% 1 53 0me 50 2% 1 50 0 as 49 2% 1 49 0 ar 46 2% 1 46 0 ur 44 2% 1 44 0 we 42 2%1 42 0 al 41 2% 1 0 41 le 42 2% 1 42 0 ce 38 1% 1 38 0 ed 38 1% 1 38 0hi 35 1% 1 0 35 be 34 1% 1 34 0 om 33 1% 1 0 33 ng 33 1% 1 33 0 il 34 1%1 0 34 wi 32 1% 1 32 0 st 32 1% 1 0 32 ow 31 1% 1 31 0 ad 30 1% 1 30 0ut 28 1% 1 28 0 am 30 1% 1 0 30 ac 28 1% 1 28 0 os 29 1% 1 29 0 av 22 1%1 22 0 ir 22 1% 1 22 0 us 27 1% 1 27 0 ea 25 1% 1 25 0 nt 24 1% 1 0 24ay 21 1% 1 21 0 ch 20 1% 1 20 0 co 22 1% 1 22 0 ho 20 1% 1 0 20 wh 19 1%1 19 0 2643 2199 444 Digraph Factor 83%

TABLE IV Opposite Hand Digraph Factors for Various Keyboards DigraphElements Opposite Same Digraph Keyboard Type Hand Hand Factor “XPeRTKeyboard” with Two Es 2199 444 83% “XPeRT Express 2174 469 82% Keyboard”(with One E) Dvorak 2124 519 80% “X” 2092 551 79% “XPeRT Keyboard” withOne E 1924 719 73% Alphabetic/Parkinson 1437 1206 54% Qwerty/Standard1330 1313 50% ASER/Romberg 1191 1452 45% Red Hot/Choate 1497 1146 57%Central/Armel 1287 1356 49%

Therefore, the XPeRT Keyboard, as well as Dvorak and “X” keyboards, arebetter optimized for speed, in terms of digraph placements, than theParkinson Alphabetic keyboard, which is viewed as “best-in-class” amongAlphabetic keyboards, in this regard. Recall that Dvorak, “X” andAlphabetic keyboards all use the degree of freedom allowed by movingvirtually all letters from known Qwerty locations. The “XPeRT Keyboard”is able to achieve similar or better speed optimization, whileminimizing the change from Qwerty at the same time.

One of the Parkinson Alphabetic options mentions the possible use of asecond key for the letters O or E, but does not enter into a digraphanalysis on the subject. The claims section of the patent mentionsdouble letters, but does not specify any letters in particular. This isquite different from the use of a second “E” in the “XPeRT Keyboard”,where the second “E” key directly enhances both primary goals, namely:improving opposite hand digraphs and speed and minimizing the difficultyof transition from Qwerty for an experienced typist.

Tradeoffs in Single Finger Digraphs and Use of Small Fingers

The “XPeRT Keyboard” design recognizes that high frequency keys arebetter accessed by inner fingers. One of the original motivators for the“XPeRT Keyboard” was to move the frequently used letter “A” away fromthe left small finger location on the home row, which is viewed asextremely awkward. It is noted that the small finger shares a tendonwith the ring finger, so that it does not operate entirelyindependently. While strength is not an issue on electronic keyboards,the resultant lack of dexterity in the small finger remains a problem.Unfortunately, many keyboards leave high frequency keys in the awkwardsmall finger locations. Examples are: Dvorak: A and S “X”: O and SRomberg: A and O Choate: A and R Parkinson: A, E, and I Qwerty: A

For physical reasons, and based on feedback from users, placement ofhigh frequency letters at a small finger location is believed to be aserious design flaw. Users estimate a 30% to 50% speed reduction for acommon key at a small finger location. It also “feels” awkward. Letsestimate the impact of placing A and S at small finger locations byDvorak, with single key frequencies A-8% and S-7%. A 30% speed reductionon those two keys implies a net negative impact of 30%×15%=5%, inoverall typing speed on the keyboard.

Only four or five single finger digraphs, or letter pairs struck by thesame finger, are found on the Dvorak keyboard. Their frequency is low,as in: PU(8), GH(9), CT(6), NR(5). The random placement of keys allowssome freedom. When a keyboard retains much of the Qwerty layout, itbecomes difficult to avoid single finger digraphs entirely. The “XPeRTKeyboard” creates a noticeable single finger digraph by placing HA(66)together. This is done to improve opposite hand digraphs, such asAS(46), AR(49), AT(64), and several others. A high net benefit to speedis perceived in the movement of the letter A to the right hand side ofthe “XPeRT Keyboard” and away from an awkward small finger location.

There is a minor loss of speed due to single finger digraphs on the“XPeRT Keyboard”. Conversely, there is a significant gain by avoidingsmall finger activity. The discussion here on avoidance of small fingeruse, and the analysis of single finger digraphs applies to the “XPeRTKeyboard” with one E key. Overall, therefore, the “XPeRT Keyboard” withone E key is seen as roughly equivalent to Dvorak and “X” keyboards forspeed potential, particularly at moderate speeds, up to 60 words perminute, which apply to most typists.

The “XPeRT Keyboard” with two E keys has an opposite hand digraph factorwhich exceeds that of both Dvorak and “X” keyboards and suggests highertyping speed potential. Avoidance of the use of small fingers on the“XPeRT Keyboard” is seen is a further advantage in terms of comfort andspeed.

Considering the “Feel” of a New Keyboard Layout

The feel of a new keyboard is considered to have two main components,namely the sense of ease derived directly from the layout and the easewith which someone familiar with typing on a Qwerty keyboard can make atransition to the new keyboard. It has been hypothesized that some ofthe more difficult transitions, for an experienced Qwerty keyboard userto make, will include the following:

1. Movement of more frequently used keys

2. Movement of frequently used keys to a location accessed by smallfingers

3. Movement of keys from the left hand side to the right hand side orvice versa

4. Movement of keys to hidden locations on the lower row

All of these concerns have been validated by experience in user trials,except number 4. Surprisingly, the “Y” location was found to be hard toreach. Conversely, the hidden old “N” location on the lower row wasfound to be easy to access. Both “E” and “G” were at one time placed inthe “Y” location, but were found difficult to access there (there was amental and physical resistance to the 427 location). This is just oneexample of considering “feel” in the new layout. Changes involving V, Y,O, U, D and other letters were considered in the “XPeRT Keyboard” designprocess and dismissed, due to awkward feel. A great deal of fine tuninghas taken place on the feel of the “XPeRT Keyboard”, as will benecessary for user acceptance.

Replacing Qwerty with Something Visible

Last, it was deemed necessary to replace the Qwerty sequence on the lefthand side of the top row with an alternate visible sequence. It waspossible to create the acronym “XPeRT” on the left hand side of the toprow. The acronym is applicable for keyboards with one or two Es, whereit represents either of the sequences X, P, R, T or X, P, E , R, T. The“XPeRT” acronym involves a rotation of the letters X, Q, J, P, and W.These changes interfere with transition from a Qwerty keyboard, but wereviewed as necessary, to readily differentiate the superior “XPeRTKeyboard”, from the slow Standard, namely Qwerty. Further, X, Q, and Jare low frequency letters and have little impact on relearning thelayout. Keeping W on the left hand side produces a relatively good“feel”.

A Summary of Keyboard Attributes

Considering all of the design objectives of the “XPeRT Keyboard”, andthe information presented above, its attributes are now summarizedrelative to that of other types of keyboards. Note that this discussionis directed specifically at the “XPeRT Keyboard” with one E key. Theaddition of a second E key adds further advantages.

The “XPeRT Keyboard” has been examined in terms of digraphs on oppositehands, avoidance of small fingers and single finger digraphs. Itcompares favourably with Dvorak and “X” keyboards in these areas. Thelatter keyboards are acknowledged as optimized for speed. The “XPeRTKeyboard” has the added constraint that as few letters as possibleshould move from their Qwerty locations. It has been surprising that the“XPeRT Keyboard” could be so well optimized for speed, with this addedboundary condition.

ASER and Red Hot keyboards are of particular interest here, since bothkeyboard designs were aimed at easing transition for an experiencedQwerty keyboard user. Unfortunately, an emphasis on the middle or homerow causes six high frequency letters to be moved from their existingQwerty locations, on both of those keyboards. While that is a positiveattribute, with respect to minimizing reach and finger strain, it is notthe only way to achieve faster typing speeds. Both in theory and inpractice, it is evident that transition from Qwerty is much easier whenas few as three high frequency keys move from their Qwerty locations, asoccurs in the “XPeRT Keyboard” designs.

The “XPeRT Keyboard” design achieves higher typing speeds not by placingall high frequency keys on the home row, but by maximizing digraphs onopposite hands. It is noted that ASER and Red Hot keyboards are not welloptimized with regard to digraphs on opposite hands and both have twohigh frequency letters at small finger locations. For these reasons,speed limitations are seen in those keyboards. The “XPeRT Keyboard” isnovel and unique, in that it offers significant speed improvements overASER and Red Hot keyboards, while simultaneously making the transitionfrom Qwerty much easier.

The “XPeRT Keyboard” offers a broader range of positive performanceattributes than other keyboards discussed here, with the exception ofreduction in finger strain. If someone suffers from finger strain oruses a keyboard for eight hours a day, that user may benefit more from ahome row oriented keyboard than an “XPeRT Keyboard”. For the majority oftypists, however, many of whom are hunt style typists rather than touchtypists, the “XPeRT Keyboard” offers dramatic speed improvements withlittle effort in transition from Qwerty.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Qwerty

This is a plan view of the Standard Qwerty keyboard, invented by C. L.Sholes and implemented on typewriters around 1872. The alphabeticcharacters or letters are numbered sequentially from 1 to 26 in theirQwerty locations, to identify key locations by number.

FIG. 2: Dvorak

This is a plan view of the Dvorak keyboard from a 1936 U.S. patent,aimed at increasing typing speed and reducing finger reach, with anemphasis on the home row. The majority of the letters in the alphabet(24 of 26) have moved from their Qwerty locations.

FIG. 3: “X”

This is a plan view of a dextral keyboard from a 1974 U.S. patent by“X”, with many of the same attributes as the Dvorak keyboard. It alsoconsiders languages other than English and has left handed (sinistral)and right handed (dextral) versions.

FIG. 4: ASER

This is a plan view of an ASER keyboard from a 1992 U.S. patent byRomberg. The layout places frequently used letters on the home row andkeeps 14 letters in Qwerty locations.

FIG. 5: Red Hot

This is a plan view of a Red Hot keyboard version from a 1998 U.S.patent by Choate; other versions have up to 12 letters on the home rowand move numerals from the top row of the keyboard to a bottom row. Thelayout shown places frequently used letters on the home row to reducereach and keeps at least 12 letters in Qwerty locations.

FIG. 6: Central

This is a plan view of a centrally oriented keyboard from a 1999 U.S.patent by Armel. In this layout most letters have been moved from theirQwerty locations. The most frequently used letters are in the center,accessible to inner fingers, as shown in an outlined area.

FIG. 7: Alphabetic

This is a plan view of an Alphabetic keyboard example from a 2000 U.S.patent by Parkinson. Letters are arranged in alphabetical order, withthe first half of the alphabet on the left hand side of the keyboard. Asmall Y is used for keys with optional characters.

FIG. 8: XPeRT One

This is a plan view of one version of the “XPeRT Keyboard”, with one keyfor the letter E. The layout is optimized to increase typing speed,while minimizing change from Qwerty.

FIG. 9: XPeRT Express

This figure shows a plan view of a keyboard example modified from thelayout shown in FIG. 8. It swaps three further letter pairs on six keys,to increase opposite hand digraphs, while retaining the underlyingstructure of the “XPeRT Keyboard” with one E key.

FIG. 10: XPeRT Two

This is a plan view of an enhanced version of the current invention,which is optimized to increase typing speed, while minimizing changefrom Qwerty. A second key is dedicated to the letter E. All letterswhich have moved from their Qwerty locations are shown in rectangles andthe double letter E is highlighted by a rectangle and a circle.

BEST MODE OF CARRYING OUT THE INVENTION

“XPeRT Keyboard” With One “E” Key.

Based on all of the considerations discussed in the Detailed Descriptionof the Invention above, the keyboard layout in FIG. 8, the “XPeRTKeyboard” With One “E” Key, was derived. Changes important to thepreferred embodiment are outlined for each key that moves in location,relative to that of the Standard Qwerty layout, shown in FIG. 1 of theDrawings.

“A” a high frequency letter, moves away from the awkward small fingerlocation on the left hand side at key number [11] and acquires adexterous finger location, below the right forefinger on the home row atkey number [17]. Frequent digraphs are separated on opposite hands, withfrequency sums such as: AS(49), AR(46), and AT(64). Typing the phrase:“as great as cats” becomes efficient, rather than an exercise infrustration, due to “one-handed” typing. A similar improvement may beachieved by placing “A” at any location on the right hand side of themiddle row, except the small finger location, that is, the old locationof the punctuation marks, semi-colon/colon.

“E”, at [3] is moved to the right hand side of the keyboard, taking aninner finger location on the home row, formerly occupied by the lowfrequency letter “K” at [18] in the Qwerty layout. “K” moves as noted inthe next paragraph. The new “E” location improves frequent digraph sums,such as: ER(162), ET(65), EV(59) and ES(57), among others. A similarimprovement may be achieved by placing “E” at the old location for theletter “J”.

In a keyboard with only one key for the letter “E”, movement of “E”creates a gap between the new location for “P” at [2] and the letters“R” and “T”. This may be closed by shifting the letters “R”, “T” and “Y”one position to the right, to key numbers [3], [4] and [5]. The new gap,at key number [6] is filled by a low frequency letter, namely “K”.Keeping “R” and “T” on the left hand side of the keyboard places manyhigh frequency digraphs on opposite sides of the keyboard. Some examplesare: TH(149), OR(65), AR(46), RU(44).

“J” from [17] has been displaced by “A”. As a low frequency letter, itmoves to an awkward small finger location, namely the former location of“P” at [10] on the Qwerty layout.

The letters “N” and “G” exchange locations, relative to their Qwertylocations, at [15] and [25]. This puts “N” on the right hand side of thekeyboard, and places more digraphs across opposite hands. Some of thedigraph sums are: AN(92), IN(88), ON(76) and EN(66). Only NT(24) issacrificed to the same hand, making this a good move. “N” may be swappedwith alternate letters, such as “D” or “F”, with only slightly differentresults.

Last, “Q” from [1] moves down to the old Qwerty “A” or [11] location and“X” from [21] replaces “Q” at [1]; “W” from [2] moves down to the oldQwerty “X” location [21]; “P” from [10] replaces “W”. These moves aremade to differentiate the Keyboard, replacing the upper row left handside letters Qwerty, by the new acronym: “XPeRT”.

This version of the instant invention may be called the “XPeRTKeyboard”, since the letters X, P, R, T appear on the left side of theupper row of the keyboard. Only three high frequency keys are moved (A,E and N); their new dexterous inner finger locations are an asset forboth usage and for relearning. They feel right. Three medium frequencykeys (G, P and W) are moved and four low frequency keys (J, K, Q and X)are moved. The impact of moving the low frequency keys is felt to beminor.

Once a user is comfortable with the “XPeRT Keyboard” configuration asdescribed here, it is possible to adapt it to further levels. Startingwith the “XPeRT Keyboard” in FIG. 8, which may become familiar to auser, a second set of key changes can be applied to optimize speedfurther. For example, the placement of digraphs on opposite hands can beimproved by:

Exchange of the letters “M” at [26] and “Z” at [20],

Exchange of the letters “B” at [24] and “L” at [19], and

Exchange of the letters “D” at [13] and “H” at [16].

This variant is called the “XPeRT Express Keyboard”, with changes toletters M, Z, B, L, D, and H, as listed here, and shown in FIG. 9 of theDrawings. As shown in the example, further incremental improvements canbe made in the placement of digraphs on opposite hands and differentlevels of performance may be achieved thereby. These build upon the“XPeRT Keyboard” base, with which a user may become familiar. Similarimprovements should be obvious to someone skilled in the art afterreviewing the approach to tradeoffs and new principles outlined herein.Such variants are viewed as falling within the scope of the embodimentsof the instant invention.

“XPeRT Keyboard” With Two “E” Keys.

A more powerful version of the “XPeRT Keyboard” has also been introducedin the Detailed Description of the Invention. Its preferred embodimentis shown in FIG. 10, called the “XPeRT Two” keyboard, a layout with two“E” keys. Key movements are as described above for the case with one “E”key, including all key numbers referenced, with the followingdifferences. “Old” key locations refer to the Standard Qwerty keylocations.

The letter “E” remains in its old location on the Qwerty keyboard at keynumber [3]; consequently the letters R, T, and Y remain in their oldlocations and do not shift to the right. A second or new key dedicatedto the letter “E” appears in the old “K” location at [18]; “K” shiftsover to the old “comma” location (a punctuation mark) at key number[27]. The punctuation mark comma moves to the old location of aninfrequently used symbol, like tilde (“˜”). Tilde is removed from thekeyboard and may be accessed through symbol tables.

In this manner, additional digraphs appear on opposite hands. As above,the most frequent digraph, ER(162), is struck by opposite hands. Inaddition, the frequent digraphs EH(117), EL(42) and EM(50) are preservedacross opposite hands, in the “XPeRT Two” layout of FIG. 10, with an Ekey accessed by both hands.

As discussed, creation of two “E” keys has multiple advantages:

It eases transition for experienced Qwerty users

It splits the use of the most frequent letter over two fingers on twohands and reduces the effort expended by each finger striking the “E”key

It increases digraph access by opposite hands, improving typing speed

The benefits of creating a double “E” key may also be associated withany of the other high frequency letters, namely A, I, O, N, R, S, and T,to a lesser degree. As the next most frequent letter after “E” inEnglish, “T” would be a good candidate as a letter with two dedicatedkeys. Similarly, for a keyboard to be used mainly in the Germanlanguage, the most frequent letter in that language, the letter “A”,would be a good candidate for a double key. The design principleintroduced here applies to all frequent letters, where the benefits of adouble key are roughly proportional to the frequency of that letter in agiven language.

Implementation in Software or Hardware

The “XPeRT Keyboard” may be implemented on most computers or data entrydevices via a simple software change in the system keyboard definitionfile, accompanied by a physical exchange of keycaps. The latter is easyto do on most keyboards; the keycaps just pop off and can be moved andreset. Alternately, software or hardware may be used to interceptkeystroke information at a keyboard connection or driver interface. Anintercept approach is more difficult, due to slight variations ininterfaces for all components on the market. In any case, these arewell-known software and hardware techniques. They are of interest hereas a way to achieve a practical implementation of the “XPeRT Keyboard”.In future, the “XPeRT Keyboard” may be implemented as off-the-shelfhardware, which will also require a new keyboard datafile, in order toremain compatible with existing keyboard hardware. The “XPeRT Keyboard”layout should also be complementary to many ergonomic keyboards, whichhave improved on the parallel row geometry of the Standard keyboard.

Combination of Positive Attributes

As outlined in the Detailed Description of the Invention, the “XPeRTKeyboard” offers a unique set of positive attributes, relative toexisting keyboards. It is highly optimized for speed, as are “X” andDvorak keyboards. At the same time, “XPeRT Keyboard” minimizes changefrom the Qwerty keyboard, while Dvorak changes the location of virtuallyall letters, making transition difficult for experienced typists. The“XPeRT Keyboard” layout does not focus on reduction of finger strain anddoes not move all high frequency letters to the home row. In thismanner, difficulty in relearning the layout is minimized, while speed ismaximized. It is important to note that the majority of these benefitsaccrue in the “XPeRT Keyboard” with one E key and that benefits simplyincrease with the addition of a second E.

For example, the author was able to increase typing speeds by 60%, afteronly a few days of use of an “XPeRT Keyboard” with one E key. A largedocument was written, but no special keyboard training exercises wereundertaken. After introduction of a second E key, improvement in typingspeed quickly jumped to 100%. Such dramatic improvements were obtainedwith little effort. As well, the combination AS is now a breeze.

Usefulness of the Invention

As stated initially, the Qwerty Keyboard was intentionally designed toslow down typing, to prevent jamming of keys on mechanical typewriters.Decades after the invention of the electronic typewriter and thecomputer, the mechanical typewriter is virtually extinct. One can onlyspeculate at the total lost industrial productivity due exclusively tothe Qwerty keyboard, since the 1930's when electronic typewriters wereinvented. The time is long overdue, to rescue typists from the past andfrom the constraints of 1872, which remain embodied in the Qwertykeyboard today, one hundred and thirty years later. It is hoped that the“XPeRT Keyboard” may provide a practical means to achieve this goal.

1. A keyboard for computers or electronic data entry devices or thelike, having a plurality of alphabetic characters or letters assigned tokeys in a region of three rows, wherein said region is comprised of amiddle row, an upper row above the middle row and a lower row below themiddle row, and said region has sequential key numbers from left toright, which correspond to letter assignments on a Standard Qwerty keylayout as follows: on the upper row, sequential key numbers 1 through 10correspond directly to the letters Q through P, in order from left toright, and on the middle row, sequential key numbers 11 through 19correspond directly to the letters A through L, in order from left toright, and on the lower row, sequential key numbers 20 through 26correspond directly to the letters Z through M, in order from left toright, and wherein said region has a left hand side defined by the keynumbers: 1 to 5, and 11 to 15, and 20 to 23, inclusive, and wherein saidregion has a right hand side defined by the key numbers: 7 to 10, and 16to 19, and 25 and 26, inclusive, and said keyboard includes: the vowelsA and E, located on said right hand side of the middle row, and theconsonants S and N, located on said left hand side of the middle row,and the consonants R and T, located on said left hand side of the upperrow, and the vowels U, I, and O, located on said right hand side of theupper row.
 2. A keyboard, as claimed in 1, wherein: the letters R, T, S,I and O remain in their current Standard Qwerty keyboard locations atsaid key numbers 4, 5, 12, 8 and 9, respectively, or have not moved morethan one adjacent key position within the row on which they arecurrently located.
 3. A keyboard, as claimed in 1, including: twoseparate keys representing at least one of the letters A, E, I, O, N, R,S or T, wherein one of these keys is located on said left hand side andthe second of these keys is located on said right hand side of saidkeyboard.
 4. A keyboard, as claimed in 1, including: two separate keysfor the letter E, wherein one of these keys is located on said left handside and the second of these keys is located on said right hand side ofsaid keyboard.
 5. A keyboard, as claimed in 1, including: two separatekeys for the letter T, wherein one of these keys is located on said lefthand side and the second of these keys is located on said right handside of said keyboard.
 6. A keyboard, as claimed in 1, including: twoseparate keys for the letter A, wherein one of these keys is located onsaid left hand side and the second of these keys is located on saidright hand side of said keyboard.
 7. A keyboard, as claimed in 1,including: the letters X, P, R, T located on the left hand side of theupper row, in that relative order, from left to right.
 8. A keyboard, asclaimed in 4, including: the letters X, P, E, R, T, in that order fromleft to right, assigned to the leftmost key positions on the upper row,at said key numbers 1, 2, 3, 4, and 5, respectively.
 9. A keyboard, asclaimed in 1, wherein: no letters within the set of letters A, E, I, O,N, R, S and T are placed at a key location which is accessed by a smallfinger, and those small finger locations correspond to said key numbers1, 10, 11 and 20 and one key to the right of key number
 19. 10. Akeyboard, as claimed in 4, wherein: no letters within the set of lettersA, E, I, O, N, R, S and T are placed at a key location which is accessedby a small finger, and those small finger locations correspond to saidkey numbers 1, 10, 11 and 20 and one key to the right of key number 19.11. A keyboard, as claimed in 1, wherein: no more than ten letters havemoved key locations relative to current locations on a Standard Qwertykeyboard.
 12. A keyboard, as claimed in 4, wherein: no more than tenletters have moved key locations relative to current locations on aStandard Qwerty keyboard.
 13. A keyboard, as claimed in 1, comprised of:the vowels A and E assigned to key numbers 17 and 18, wherein these twovowels may appear in either the order A, E or the order E, A from leftto right, and the consonant N assigned to key number 15, and theconsonant G assigned to key number 25, and a plurality of keysrepresenting the remaining letters of the alphabet.
 14. A keyboard, asclaimed in 4, comprised of: the vowels A and E assigned to key numbers17 and 18, wherein these two vowels may appear in either the order A, Eor the order E, A from left to right, and a second vowel E assigned tokey number 3, and the consonant N assigned to key number 15, and theconsonant G assigned to key number 25, and a plurality of keysrepresenting the remaining letters of the alphabet.
 15. A keyboard, asclaimed in 1, comprised of: the consonants R and T assigned to keynumbers 3 and 4 respectively, and the vowels U, I, and O assigned to keynumbers 7, 8, and 9 respectively, and a plurality of keys representingthe remaining letters of the alphabet.
 16. A keyboard, as claimed in 4,comprised of: the consonants R and T assigned to key numbers 4 and 5respectively, and the vowels U, I, and O assigned to key numbers 7, 8,and 9 respectively, and a plurality of keys representing the remainingletters of the alphabet.
 17. A keyboard, as claimed in 15, comprised of:the vowels A and E located at key numbers 17 and 18, wherein these twovowels may appear in either the order A, E or the order E, A from leftto right, and the consonant N located at key number 15, and theconsonant G located at key number 25, and a plurality of keysrepresenting the remaining letters of the alphabet.
 18. A keyboard, asclaimed in 16, comprised of: the vowels A and E located at key numbers17 and 18, wherein these two vowels may appear in either the order A, Eor the order E, A from left to right, and a second vowel E assigned tokey number 3, and the consonant N located at key number 15, and theconsonant G located at key number 25, and a plurality of keysrepresenting the remaining letters of the alphabet.
 19. A keyboard, asclaimed in 17, wherein: no letters within the set of letters A, E, I, O,N, R, S and T are assigned to a key which is accessed by a small finger,and those small finger locations correspond to said key numbers 1, 10,11 and 20 and one key to the right of key number 19, and no more thanten letters have moved key locations relative to current locations on aStandard Qwerty keyboard, and the letters X, P, R, T are located on theleft hand side of the upper row, in that relative order, from left toright.
 20. A keyboard, as claimed in 18, wherein: no letters within theset of letters A, E, I, O, N, R, S and T are assigned to a key which isaccessed by a small finger, and those small finger locations correspondto said key numbers 1, 10, 11 and 20 and one key to the right of keynumber 19, and no more than ten letters have moved key locationsrelative to current locations on a Standard Qwerty keyboard, and theletters X, P, E, R, T, in that order from left to right, are assigned tothe leftmost key positions on the upper row.